Bury a container as a wine cellar

[Puttsan]

I have a small idea, I am in the planning stage of building a roughly 20 sqm glassed-in patio.

And I've got a fixed idea I would like to discuss.

I have a reasonably non-rusty 10-foot container with a broken door that I no longer have use for and came up with the idea of possibly using it as a wine cellar under the new patio.

The idea is as follows:

• Dig a hole.
• Dump down gravel or similar.
• 200mm foam plastic.
• Cast a 100mm concrete slab.
• Spray/foam insulate the outside of the container 100mm.
• Place the container with the opening upwards.
• Build vertical framework inside to withstand the soil masses.
• Refill with gravel or similar.
• Build the patio on top.
• Spiral staircase down with a hatch.

I plan to do all the work myself except for lifting the container into the hole, as that requires a crane truck.

I thought about buying a spray insulation kit from abroad.

Questions:

How long before it rusts through when the sheet metal is on the warm side? 30 years?

 

[Svanteman]

Don't know how long the metal sheet will last but with decent drainage surely 30 years+
But remember it's a 16m³ buoy you're sinking down, it will want to float up so anchor it very well downwards with ground anchors or into rock preferably.
Alternatively, fill it with an insane amount of wine!